[32.01] High-Resolution Observations of Jupiter's 300-mbar Temperature Field by the PPR Experiment from Galileo's Europa-16 Orbit

From the ashes of Galileo's Europa-16 orbit, in which a
spacecraft safing event deleted almost all atmospheric
observations, come two sets of high-spatial resolution maps
of Jupiter's 300-mbar temperature field using the 27-\mum
radiometric channel of the Photopolarimeter-Radiometer (PPR)
experiment. The first of these is an observation of a {\it
new white oval} (see Fisher {\it et al.} this meeting),
observed at ~1800-km resolution. The oval is
unmistakenly defined as a distinct cold feature,
~10,000 - 18,000 km, roughly commensurate with the same
feature as defined by high-altitude particulates observable
in the near infrared (again,see Fisher {\it et al.}). The
300-mbar temperature of the interior of the spot,
~115.8 K, is uniform to the extent of our spatial
resolution and ~1.2 K colder than the general
surroundings. The oval appears to be surrounded by a narrow
ring at the limit of our spatial resolution that is
~0.5 K warmer than the surrounding material. The spot
lies to the immediate north of a region that is uniformly
about 1 K warmer than the general area at the latitude of of
the white oval. The second region mapped is a {\it broad
area in the northern hemisphere} from 3\circ to
27\circN planetocentric latitude and 35\circ to
100\circ System-III longitude, observed at ~1600-km
resolution. The latitude range includes portions of the
axisymmetric features known as the Equatorial Zone (EZ),
North Equatorial Belt (NEB), North Tropical Zone (NTrZ) and
the North Temperate Belt (NTB). There is much detail in the
temperature structure, with a temperature range from 124.8 K
in the peak of a NEB wave to 117.0 K in the coldest part of
a NTrZ zonal wave. The warm NTB extends further south than
its boundary in the visible or 5-\mum cloud field. There
is striking zonal wave structure in the NEB, and
considerable detail is apparent at the smallest spatial
scales. High temperatures are correlated with the width of
the NEB in the thermal field. These, in turn appear to be
correlated with the width of the NEB in the cloud field and
the longitudes of 5-\mum hot spots, perhaps
coincidentally. There is a clear mixture of large- and
small-scale structure correlations and non-correlations
between the temperature and cloud fields that must be sorted
out.

The author(s) of this abstract have provided an email address
for comments about the abstract: go@orton.jpl.nasa.gov